On clomid (clomiphene) -confirmed ovulation. cramping @ 7 dpo. 1 painful cramp then mild cramps for a few hours. how to tell if menstrual or implantation cramping?

You really can't: I am not sure exactly what you mean by implantation cramping. Cramps could be from anything in the pelvis - uterus, ovaries, bladder, rectum and intestines. It is not really possible to guess which organ is responsible at any one time. If you miss your period then check a home pregnancy test. Until then you just have to patiently wait. Best of luck to you.